Position selector device for wells



Nov. 26, 1963 w. J. HAYES 3,111,990

POSITION SELECTOR DEVICE FOR WELLS Filed Nov. 7, 1960 s Sheets-Shet 1FlG.l

INVENTOR:

W. J. HAYES HIS ,AGENT Nov. 26, 1963 w. J. HAYES 3,111,999

POSITION SELECTOR DEVICE FOR WELLS Filed Nov. 7, 1960 3 Sheets-Sheet 2FIG. 9

as o 86 74 7s FIG. 2

INVENTORII w. a. HAYES HIS AGENT United States Patent 3,111,990 POSI'HGNSELECTOR DEVICE FOR WELLS William J. Hayes, Houston, Tex., assignor toShell Oil Company, New York, N.Y., a corporation of Delaware Filed Nov.7, 1960, Ser. No. 67,647 8 Claims. (Cl. 166-64) This invention relatesto a well device adapted to be moved up or down a string of tubingpositioned within a well and pertains more particularly to a deviceadapted to be pumped through a well tubing preferably together with awell tool connected thereto whereby the tool may be seated at apredetermined position within the well. In addition to positioning toolsat a predetermined position within a well tubing, it is often desirableto position other well devices, instruments or equipment, for example,gas-lift valves, etc, or to carry out certain operations, for example,opening or closing a valve in the tubing.

A recent development in the oil industry is the drilling and completionof wells at an offshore location where the wellhead assembly andproduction control units are po sitioned beneath the surface of a bodyof water and preferably close to the bottom of the body of water. Withwellhead assemblies positioned on an ocean floor, a hazard to thenavigation of boats in offshore waters is removed. Additionally,considerable savings are realized in that it is not necessary to erect aprotective stationary platform around the wellhead in the manner inwhich they are presently employed to protect well casing and well headassemblies extending above the surface of the water. It has also beenfound necessary to position a wellhead on the ocean floor in waterdepths where it is not feasible to erect a stationary platform around awellhead assembly.

However, the placement of wellhead assemblies on the ocean floor raisesa new set of problems with regard to carrying out workover operations,maintenance or other operations in a completed well. Major workoveroperations call for the use of a barge positioned on the surface of thewater above the well together with equipment for going down and enteringthe wellhead assembly and the tubing or casing strings connectedthereto, and in some circumstances may result in the entire removal ofthe wellhead assembly to the surface during workover operations. Inorder to carry out some of the more simple workover or maintenanceoperations, such as the perforation of well casing, the opening of apacker, the removal or insertion of a valve, the cleaning of paraffinfrom a tubing string, the opening or closing of a sleeve valve, etc., ithas been necessary to develop an entirely new line of well tools whichcan be pumped through a production tubing string from some remotelocation, oftentimes a mile or more from the well, and enter the well,passing down the tubing string therein to be subsequently positionedtherein for carrying out some preselected operation. After completingthe operation, the tool in the tubing string within the well issubsequently removed, generally by reverse circulation.

While the problem of pumping a tool to the bottom of a well tubingstring in order to carry out certain operations is fairly readilysolved, the problem of pumping a certain tool, device or other apparatusto a certain predetermined position within a well tubing is far moredifficult. This is especially true in the event that it is necessary toposition the tool or other device in one of a series of identicallocations within a well tubing. Thus, for example, a well tubing may beprovided with a series of gas-lift valves spaced at various intervalsalong the length of the tubing. In replacing gas-lift valves in a welltubing it is necessary to be sure to get the newly well tubing.

Likewise, a well tubing string may be provided with one or more sleevevalves at spaced intervals therea-long or at various depths. At times itis desirable to open or close selectively one or more of these valves atcertain designated levels while allowing any remaining valves tomaintain their previous setting.

It is an object of the present invention to provide apparatus adapted topass through a well tubing and automatically bypass a plurality ofseating positions therein until arriving at and subsequently beingseated in a preselected position.

Another object of the present invention is to provide an apparatusadapted to be pumped through a string of pipe in a well and aroundcurved portions thereof which may be located in and/or outside a well,the apparatus being pumped together with a well device and subsequentlybeing stopped at a preselected location in the pipe string.

A further object of the present invention is to provide apparatusadapted to pass through a well tubing and automatically seat itself in apreselected recess of a plurality of recesses spaced along a welltubing, and subsequcntly be energized to perform an operation such asopening or closing a valve.

These and other objects of this invention will be understood from thefollowing description taken with reference to the drawing, wherein:

FIGURE 1 is a schematic view illustrating a wellhead assembly positionedon the ocean floor;

FIGURE 2 is a diagrammatic view taken in longitudina-l cross-section ofa tubing string with the apparatus of the present invention positionedtherein;

FIGURE 3 is a longitudinal view taken in cross-section of the positionselector device of the present invention;

FIGURE 4 is a longitudinal cross-sectional view of the position selectordevice of the present invention taken at degrees to FIGURE 5;

FIGURES 5, 6, 7 and 8 are cross-sectional views taken along the lines5-5, 6--6, 77, and 88 of FIG- URE 3, respectively; and

FIGURE 9 is an isometric view of one of the upper latching dogs of theapparatus of FIGURE 3.

Referring to FIGURE 1 of the drawing, a wellhead assembly is shown aspositioned below the surface 11 of a body of water and preferably on theocean floor 112. The wellhead apparatus comprises a platform 13 securedto the top of a conductor pipe or surface casing 1 which in turn extendsinto the earth below the body of water and is preferably cementedtherein in a conventional manner. The wellhead assembly may also beprovided with two or more vertically positioned guide columns 15 and 16which are fixedly secured at their lower ends to the platform 13. A wellcasing head 17 is mounted on the top of the conductor pipe 14 with acontrol equipment housing 18 closing the top of the casinghead and/ orany casing and tubing suspension equipment employed on the wellheadassembly, as well as the various control valves and other controlequipment normally used on the top of a well of this type.

Emerging from the housing 18 are a pair of flow lines 26 and 21 whichpreferably bend in long sweeping curves from a vertical position down toa substantially horizontal position so that they can run along the oceanfloor 12 to a remote location where fluid from the well, and normallyfrom other wells, is collected and metered and treated. Such acollection station may be several miles away. During the production ofthe well, normally only one of the flow lines 2% or 211 is employed intransporting fluid away from the well. The well may be provided with oneor more strings of well casing 22 suspended within the well. However, inother well installations wherein a single tubing string is utilized, thesecond flowline may be in communication with the annular space betweenthe tubing string and the adjacent well casing. For purposes ofillustrating the apparatus of the present invention, one of the tubingstrings 23 in FIGURE 1 will be considered as being provided with aseries of sleeve valves in spaced relationship along the tubing string.

Referring to FIGURE 2, it may be seen that the tubing string 23 isprovided with suitable means for stopping a well tool or other device asit passes or is pumped through the tubing string. The stop means withinthe tubing string 23 may take the form of a sleeve valve 25 having arecessed portion 26, for example, which is shown as hav- 'ng an internaldiameter greater than that of the internal diameter of the tubing string23. In the particular recessed portion 26 illustrated, a seating or stopshoulder 27 is formed at the bottom thereof while another shoulder 28 isformed at the top thereof. In the event that no sleeve valve 25 isemployed within the tubing string 23, the stop means within the tubingstring may take the form of e recessed portion 26 in which the sleevevalve 25 is slidably mounted, with shoulder 31 forming the downwardlimiting stop.

Arranged for sliding movement through the tubing string 23 is theposition selector device 31 of the present invention to which may beattached a well tool, device, instrument or other element (not shown),for example, a valve opening and/or closing device which is designed tobe positioned at a predetermined location in the tubing string, such forexample as in the recessed portion 26 of a particular sleeve valve 25which it is desired to open or close. If it is desired that theinstrument or tool and the position selector device be pumped intoposition through the tubing string 23, which would be the normalprocedure, one or more rubber motor swab elements of a type described incopending application, Serial No. 45,036, filed July 25, 1960, isprovided. The motor swab cups 32 and 33 may be directly connected to theinstrument or tool or it may be connected to the position selectordevice 31 of the present invention which in turn is connected to theinstrument or tool. The motor swab elements 32 and 33 may be arrangedabove and below the apparatus of the present invention, as illustratedin FIG- URE 2, or both of them may be arranged above or both below theapparatus, or pairs of them may be carried above and below. In any pairof swabs, one is preferably arranged to expand when the apparatus isbeing pumped down the tubing while the other expands when the apparatusis pumped in the opposite direction. Alternatively, the apparatus may beprovided with a fishing head 39 so that motor swabs could be circulateddown to tubing to attach to the fishing head prior to pumping theapparatus up the tubing. Preferably, all connections, such as 35 and 36,are in the form of flexible joints such as a short section of hose or aball-and-socket joint whereby the connected elements may pass readilythrough curved sections of the tubing string 23. It is to be understoodthat the tubing string 23 may be provided with a plurality of therecessed portions 29 or valves with recessed portions 26, which may bespaced, say, several hundred feet apart.

The position selector device shown in FIGURES 3 and 4 comprises ahousing member 37 having a recess 38 formed therein near one end thereofin which a pair of latching dogs 41 and 42 are mounted on pivot pins 43and 44 for radial expansion outwardly from the housing member 37 so asto contact the seating shoulder 27 of the recessed portion 26 of thesleeve valve 25 in the tubing string 23 (FIGURE 2). The outer faces ofthe lower portions 45 and 45a of the latching dogs 41 and 42 arepreferably of a length and shaped at an angle so that when the latchingdogs are in their extended position against the inner walls of a tubingstring 23, the latching dogs 41 and 42 will readily pass over any jointformed between two sections of the tubing string without hanging uptherein. A compression spring 47 is mounted between the latching dogs 41and 42 for normally urging the latching dogs 41 and 42 outwardly. Thelatching dogs 41 and 42 are normally retained in a retracted orinoperative position, as illustrated in FIGURE 3, by any suitable meansas by a pair of telescoping sleeves 50 and 51 which surround the spring47. When the sleeves 50 and 51 are in their shortest telescopedposition, a pair of holes through the sleeves are in register with eachother allowing a pin 52 at the lower end of a slidable arm 53 to passthrough the holes. Since each sleeve 50 and 51 is secured at one end toone of the latching dogs 41 and 42, the latching dogs 41 and 42 areprevented from moving outwardly as long as the pin 52 remains positionedin the holes in the sleeves 50 and 51.

The arm 53 is slidably mounted for axial movement in bushings 54 and 55centrally located within the housing member 37. A pin 56 through the arm53 retains a compression spring 57 against lower bushing 55. Asmalldiametcr pin 60 is formed at the end of the arm 53, the pin 60being designed to fit into a slot 61 of an actuating wheel or releasingcam 62. The actuating Wheel 62 in turn is coupled to and is actuated bya counting apparatus, such for example as a two-gear reducing trainrepresented by gears 63 and 64, which operatively connect the wheel orcam 62 to a ratchet or indexing gear 66 which is actuated by aspring-loaded pawl 65.

The indexing gear or ratchet 66 engages and is actuated by the pawl 65carried at the lower end of a linkage arm 67. The upper end of thelinkage arm 67 is provided with a compression spring 68 which normallyurges the arm 67 downwardly.

The housing member 37 of the position selector device is provided with arecess 70 in which one or more feeler elements are mounted for movementoutwardly therefrom. Preferably, two pairs of feeler elements 71, 72, 73and 74 are mounted on pivot pins 75, 76, 77 and 78 for movement in aplane parallel to the axis of the housing member 37. The feeler elementsare of any suitable size and shape, preferably angular, as shown inFIGURE 3, with an arm of the elements 71, 72, 73 and 74 beingoperatively connected to the linkage arm 67, as by being in contact witha pin 81 or 82 extending through the arm 67. Rotatably mounted wheels83, S4, 85 and 86 are preferably secured to the outwardly extending endsof the feeler elements 71, 72, 73 and 74 to reduce the friction and wearas the present apparatus moves slidably through a tubing string.

The feeler elements 71, 72, 73 and 74 are provided with suitable springs87, 88, 89 and 90 arranged to urge the wheels 83, 84, 85 and 86outwardly from the housing member 37 and against the inner wall of atubing string 23 (FIGURE 2) as the position selector device passestherethrough. If two pairs of feeler elements 71, 72, 73 and 74 areemployed, as illustrated in FIGURE 3, they are connected together bylinkage arms 91 and 92 so that they operate together.

In the event that the position selector device of the present inventionis to be employed to open a sleeve valve 25 (FIGURE 2) it may beprovided with suitable means for subsequently closing the valve. Onedevice for accomplishing this operation is shown in FIGURES 3 and 4 as ahousing member 93 having a recess 94 therein in which a pair of upwardlydirected, outwardly expansible, valve-engaging dogs 95 and 96 aremovably mounted on a pair of shear pins 97 and 98. A spring 99 betweenthe dogs 95 and 96 normally urges the shear pinned dogs outwardly. Thehousing member 93 is connected to housing member 37 by flexible joint 35but it may be integrally formed thereon. The recessed portion 94 of thehousing member 37 is shaped so as to hold and retain the dogs 95 and 96in a retracted position when the pins 97 and 98 have been sheared. Theupper motor swab element 32 (FIGURE 2) is preferably provided with aninterior flow passage 100 and a check valve 101 therein arranged topermit fluid under substantial pressure to be pumped past the swabelement 32.

Prior to running through a well tubing the position selector device ofthe present invention, a determination is made as to the depth to whichthe selector device 31 (FIGURE 2) is to be lowered. For example, it maybe decided that the indicator device 31 should be actuated at a time sothat it seats itself in the recessed portion 26 of the fourth valve 25within the well tubing 23. In such a case, the ratchet 66 within thehousing member 37 would be rotated backwards for the correct number ofnotches, in this case, four notches. The indicator device 31, togetherwith any tool attached thereto, would be put in an open end of thetubing string 23 and passed therethrough until it had reached the fourthrecessed portion in the tubing string. Preferably, a motor swab 32 isattached to the position selector device 31 so that the entireassemblage, including preferably another oppositely positioned motorswab 33 attached to the other end thereof, is put into a tubing stringand the tubing string attached to a pump so that a fluid may be pumpeddown the tubing string 23 in back of the assembled elements. As theassembled tool passes down the tubing string 23, it passes the series ofsleeve valves 25.

As the position selector device passes down through a tubing string 23(FIGURE 2), the wheels 83, $4, 85 and 86 or" the feeler elements 71, 72,73 and 74 roll against the inner surface of the tubing string and expandinto any recess that is of a length greater than the distance betweenthe wheels 84 and 86 (FIGURE 3). Since the feeler elements 71, 72, 73and 74 are connected in pairs by linkages 91 and 92 it is evident thatboth pairs of feeler elements 7l73 and 72-74 must move together. Thus,no single arm of a pair of arms can expand unless both expand. With thisarrangement, no expansion of the feeler elements and hence no actuationof rod 67 and ratchet 66 takes place until the feeler elements havearrived at a recess 26 (FIGURE 2) long enough to accommodate both pairsof feeler arms at once.

When a recess 26 of suificient length is reached both pairs of feelerelements 71, 72, 73 and 74 expand outwardly, which forces the linkagearm 67 upwardly. This movement causes the pawl 65 to rotate the ratchet66 one notch. The ratchet 66 through the reduction gears 63 and 64,rotate the releasing cam 62 a fraction of a turn. T he spring 68 causesthe linkage arm 67 to follow the feeler element arms downwardly.

When the desired number of recesses or recessed portions of sleevevalves have been past so as to actuate the ratchet 66 the desired numberof times to rotate the releasing cam 62 through the proper angle, asdetermined by setting the tool before it is run, the pin 60 moves intothe slot 61, allowing the slidable arm 53 and the pin secured to thelower end thereof to travel upwardly. Upward movement of this arm 53,which is caused by the spring 57, pulls the pin 52 out of thetelescoping sleeves 50 and 51 so that they are allowed to be expanded bymeans of spring 47 which also forces the latching dogs 41 and 42outwardly. In the event that the recessed portion 26 of the sleeve valve25 is long enough (as illustrated in FIGURE 2) to accommodate both ofthe feeler elements and the latching dogs within the recessed portion atthe same time, the latching dogs 41 and 42 then move along the innerwall of the sleeve valve until they are stopped by the shoulder 27therein. In the event that the recessed portion 26 of the sleeve valve25 is not of a length great enough to accommodate the feeler elementsand the latching dogs at the same time, release of the latching dogs 41and d2 would cause the dogs to expand against the inner wall of thetubing string and ride along the wall of the tubing as the positionselector device was propelled through the tubing to the next lowersleeve valve. During this operation the length and shape of the lowerportions 45 and 45a of the latching dog would prevent the dogs fromhanging up in the tubing collars or the space between two sections ofthe tubing string. It is because of these spaces that it is preferred touse two sets of feeler elements 84 and 86 spaced axially of each otherto prevent actuation of the two in the event a feeler element expandedinto one of the spaces. Alternatively, a single pair of feeler elementsmay be employed in some situations or even a single feeler element witha larger wheel carried at the end thereof.

With the latching dogs ll and 42 seated on the shoulder 27 (FIGURE 2) ofthe sleeve valve 25, an increase in the hydraulic pressure above the twowill cause the sleeve valve 25 to move downwardly so that its ports N2and 163 are in register with ports N4 and 105 through the wall of thetubing 23.

In the event that it was planned to close the sleeve valve 25 a shorttime after it had been opened, the auxiliary housing member 93 with itsupwardly directed latching dogs 95 and 96 would have been attached tothe position selector device 31 at the time the position selector devicewas run downwardly through the tubing string 23. The dogs 95 and 96 areexpanded when the device is first put in the tubing string 23 and theydrag along the wall of the pipe as the device is pumped downwardlythrough the tubing string. In order to close the sleeve valve 25 andreturn the apparatus to the surface, circulation in the well is reversedso that the apparatus may be pumped upwardly through the tubing string.On upward movement of the apparatus through the well tubing 23, the dogs95 and 96 engage the upper shoulder 28 of the sleeve valve 25, pushingit upwardly as far as it will go to the position shown in FIGURE 2.After the sleeve valve 25 has been closed, an increase in the hydraulicpressure within the tubing string 23 from below the tool causes the pins97 and 98 (FIGURE 3) to shear, allowing the dogs 95 and 96 to be forceddownwardly into the recess 94 within the housing member 593. Furtherexpansion of the spring 99 holds the dogs 95 and 96 within the recess 9dand prevents them from later protruding and preventing recovery of thetool. With the dogs 95 and 96 retracted the apparatus may be circulatedto the top of the well again. In the event that it is desired to leavethe sleeve valve 25 open after the tool is retrieved, the upper dogs 95and 96 would not be installed when the apparatus was originally run intothe well.

In the above-described operation of the apparatus of the presentinvention, it is assumed that the motor swab cups 32 and 33 expandsufficiently during operation to engage the inner walls of the sleevevalve 25 in their operative position so as to provide a pressuredifferential across the apparatus sufficient so that it can be pumpedthrough the tubing string 23. In some cases it may be found desirable toadd additional motor swabs 32 above the presently illustrated motor swab32 of FIGURE 2, or to send down independent motor swabs (not shown) toengage the fishing head 29 at the top of the apparatus.

I claim as my invention:

1. Apparatus for selectively limiting the downward travel of a welldevice through a pipe string depending vertically within a well, saidapparatus comprising a vertical pipe string, a plurality of stop meansformed within the pip-e string at axially spaced locations therealong, apumpable well device including a position selector device of a diametersuificient to pass through said pipe string to stop selectively at oneof said stop means, latching means carried by said position selectordevice and adapted to engage one of said stop means, and latch actuatingmeans carried by said position selector device and operatively connectedto said latching means, said latch actuating means includingoutwardly-extending feeler arm means actuatable by and responsive tomovement past each of said stop means.

2. Apparatus for selectively limiting the downward travel of a welldevice through a pipe string depending vertically within a well, saidapparatus comprising a vertical pipe string, a plurality of recessedstop means formed within the pipe string at axially spaced locationstherealong, a pumpnble well device including a position selector deviceof a diameter sufficient to pass through said pipe string to stopselectively at one of said stop means, latching means carried by saidposition selector device and adapted to engage one of said stop means,latch actuating means carried by said position selector device andoperatively connected to said latching means, said latch actuating meansincluding outwardly-extending fecler arm means actuatable by andresponsive to movement past each of said stop means, and adjustablerelease means operatively connected to said latch actuating means fordelaying the operation of said latch actuating means until said positionselector device is in a preselected portion of said pipe string.

3. Apparatus for selectively limiting the downward travel of a welldevice through a pipe string depending vertically within a well, saidapparatus comprising a vertical pipe string, a plurality of recessedstop means formed within the pipe string at axially spaced locationstherealong, a pumpable well device including a position selector deviceof a diameter sufiicient to pass through said pipe string to stopselectively at one of said stop means, normally retracted, radiallyextensible latching means carried by said position selector device andadapted to engage one of said step means, latch-actuating means carriedby said position selector device and operatively connected to saidlatching means, said latch actuating means including outwardly-extendingfeeler arm means 'actuatable by and responsive to movement past each ofsaid stop means, adjustable release means operatively connected to saidlatch-actuating means for delaying the operation of said latch'actuatingmeans until said position selector device is in a preselected portion ofsaid pipe string.

4. A position-selector device of a size adapted to pass through a pipestring in a well to a selected recessed portion thereof, said selectordevice comprising an elongated body member, radially extensible latchingmeans carried within said body member, a counter mechanism operativelyconnected to said latching means for actuating said latching means onarrival at a preselected position in a pipe string, andcounter-actuating means including outwardly extending feeler arm meanscarried by said body member and operatively connected to said countermechanism for stepwise actuation of said counter mechanism, saidcounter-actuating means being responsive to movement of said feeler armmeans past recessed portions in said string through which said selectordevice moves.

5. A position-selector device of a size adapted to pass through a pipestring in a well to a selected recessed poriton thereof, said selectordevice comprising an elongated body member, spring loaded, normallyretracted radially extensible latching means carried within said bodymember, arm means in said body member and operatively connected to saidlatching means to hold said latching means normally in a retractedposition, adjustable counter mechanism connected to one end of said armmeans to actuate said arm means when said gear mechanism has arrived ata preselected position, and actuating means including outwardlyextending feeler arm means carried by said body member and operativelyconnected to said counter mechanism for stepwise actuation of saidmechanism.

6. A position-selector device of a size adapted to pass through a pipestring in a well to a selected recessed portion thereof, said selectordevice comprising an elongated body member having a chamber for-medtherein, flexible tool joint connector means carried on at least one endof said body member for connecting a well device thereto, spring-loadednormally retracted, radially extensible latching means carried withinsaid body member, arm means in said body member and operativelyconnected to said latching means to hold said latching means normally ina retracted position, an adjustable ratchet-type counter mechanismconnected to one end of said arm means to ac tuate said arm means whensaid counter mechanism has arrived at a preselected position,counter-actuating means including outwardly extending feeler arm meanscarried by said body member and operatively connected to said countermechanism for stepwise actuation of said counter iechanism, saidcounter-actuating means being responsive to movement of said feeler armmeans past vrecessed portions in the pipe string through which saidselector device moves.

7. A position-selector device of a size adapted to pass through a pipestring in a well to a selected recessed portion thereof, said selectordevice comprising an elongated body member having a chamber formedtherein, flexible tool joint connector means carried on at least one endof said body member for connecting a well device thereto, a pair ofspring-loaded normally retracted, radially extensible latching meanscarried within said body memher, arm means in said body member andoperatively connected to said latching means to hold said latching meansnormally in a retracted position, an adjustable ratchet-type countermechnism connected to one end of said arm means to actuate said armmeans when said counter mechanism has arrived at a preselected position,counter-actuating means including at least two pair of outwardlyextending feeler arm means carried by said body member in axial spacedrelationship and operatively connected to said counter mechanism forstepwise actuation of said counter mechanism, said counter-actuatingmeans being responsive to movement of said feeler arm means pastrecessedportions of the pipe string through which said selector devicemoves.

8. The apparatus of claim 7, including a second pair of spring-loadedlatching means extending outwardly from said body member, and shear pinssecuring said latching means to said body member, said latching meansbeing arranged on said body member for free movement in only onedirection through a pipe string.

References Cited in the file of this patent UNITED STATES PATENTS2,292,938 Hennessy Aug. 11, 1942 2,810,440 Kenneday et a1 Oct. 22, 19572,871,946 Bigelow Feb. 3, 1959 2,871,947 Fredd Feb. 3, 1959

1. APPARATUS FOR SELECTIVELY LIMITING THE DOWNWARD TRAVEL OF A WELLDEVICE THROUGH A PIPE STRING DEPENDING VERTICALLY WITHIN A WELL, SAIDAPPARATUS COMPRISING A VERTICAL PIPE STRING, A PLURALITY OF STOP MEANSFORMED WITHIN THE PIPE STRING AT AXIALLY SPACED LOCATIONS THEREALONG, APUMPABLE WELL DEVICE INCLUDING A POSITION SELECTOR DEVICE OF A DIAMETERSUFFICIENT TO PASS THROUGH SAID PIPE STRING TO STOP SELECTIVELY AT ONEOF SAID STOP MEANS, LATCHING MEANS CARRIED BY SAID POSITION SELECTORDEVICE AND ADAPTED TO ENGAGE ONE OF SAID STOP MEANS, AND LATCH ACTUATINGMEANS CARRIED BY SAID POSITION SELECTOR DEVICE AND OPERATIVELY CONNECTEDTO SAID LATCHING MEANS, SAID LATCH ACTUATING MEANS INCLUDINGOUTWARDLY-EXTENDING FEELER ARM MEANS ACTUATABLE BY AND RESPONSIVE TOMOVEMENT PAST EACH OF SAID STOP MEANS.